Leak-proof drinking devices are, of course, generally known, particularly for infants, which usually have a body and a lid closing the body. In one of the known constructions, for example as disclosed in UK Patent No. 2266045, the lid has an outlet for dispensing liquid and an air inlet for pressure balance, both of which are provided with respective one-way valves to protect against leakage.
Liquid is to be extracted from inside the body through suction applied to the outlet. While the valve of the outlet should be closed reasonably tightly normally, it has to be opened relatively easily to facilitate drinking. None of the known devices is found to be satisfactory in this regard.
The invention seeks to mitigate or at least alleviate such a problem by providing an improved drinking device.